The Lability of Riverine Particulate Organic Carbon Delivered to the Ocean

每年从陆地到海洋的大量有机碳通量在海洋中基本消失。这种损失的原因尚不清楚。根据该奖项，PI将研究河流颗粒有机物损失的不稳定性的非生物和生物方面。工作将集中在密西西比河，因为它证明了任何北美河流在海洋中沉积时颗粒有机物质的最明显损失。光化学实验将在初步工作的基础上继续进行，初步工作表明颗粒有机物受到太阳辐射水平的影响会发生显著溶解。将研究与金属循环的相互作用，以及其他各种物理化学变量。将通过酶水解和细菌孵育探索生物化学不稳定性。将审查季节模式，以及淡水环境中沉积物的影响。

The large annual flux of organic carbon from land to the ocean largely disappears in the sea. Reasons for this loss are not clear. Under this award, the PI will examine abiotic and biotic aspects of the lability to loss of riverine particulate organic matter. Work will focus on the Mississippi, as it demonstrates the clearest loss of particulate organic material of any North American river upon deposition in the ocean. Photochemical experiments will follow up on initial work showing significant dissolution of particulate organic matter subjected to solar levels of radiation. Interactions with metal cycling will be studied, as will a variety of other physicochemical variables. Biochemical lability will be explored via enzyme hydrolyses and bacterial incubations. Seasonal patterns will be examined, as will be the influence of deposition in freshwater environments.